In general, inside the communication devices, a plurality of cables is used to connect power and signal between several mounted communication modules. When the cables are used in this way, since there is a basic need for an operation space for fastening and disconnecting the cables, relatively much space is required. Furthermore, since there is a need to be able to connect the cables after mounting the communication module, the position of the connecting port is also limited only to the front or the side that allows the check.
In addition to spatial limitations as described above, in order to mount and dismount the communication module in the production process, since it is necessary to assemble and disassemble the plurality of cables, it takes a lot of time, which leads to a problem of an increase in production costs.
In addition, if the communication module of the plug-in type is used, when mounting the communication modules, the connection port is disposed on an opposite side of a surface as viewed from an operator side. Therefore, there is a need for a structure which can serve as a guide so that the communication modules can be mounted at the appropriate positions. As a method for guiding the mounting position, a method of using a guide rail and a guide pin is the most general. However, in order to implement such a guide structure, since an additional space is required for the module and the housing, and in some cases, another structure needs to be added, there is a difficulty to be implemented in a device of a limited size.